The links for AD&D Unlimited and Realmspace: Genomicon are dead. If the later is the Genomicon site of Brian James, I don't think he's actively maintaining it since the Grand History became an official WotC product. He had to take down the free PDF.

His brother Matt James maintains his own site at: loremaster.org.
Brian may participate there as well, I haven't been following that site. Both participate regularly at Candlekeep and the WotC FR forums.

Candlekeep really is THE fan site for the Forgotten Realms and is more extensive than it looks. It can be broken up into a plethora of interesting links. One could find these just clicking around, or going through the very helpful site map, but some of the highlights of the site include:

Realmslore, including some official lore from WotC. Further down are the compiled forum responses from the various Realms designers and authors. The more extensive interactions are broken down by year, such as those for Ed Greenwood. http://www.candlekeep.com/library/lore.htm#lore

"A group dedicated to the Forgotten Realms campaign setting. While the group will be dedicated to all versions of Toril from 1e D&D to D&D Next (5e), it will primarily be dedicated to post-Time of Troubles era of the Realms before the Spellplague."

These things also I have observed: that knowledge of our world is to be nurtured like a precious flower, for it is the most precious thing we have. Wherefore guard the word written and heed words unwritten-and set them down ere they fade...Learn then, well the arts of reading, writing, and listening true, and they will lead you to the greatest art of all: Understanding." -Alaundo of Candlekeep.